1. Field of the Invention
The invention relates to biological soil treatment products which improve the soil biology of adventitious plants and a method for delivery directly to the plant root systems.
2. Description of Related Art
Biological soil treatments are currently marketed in a dry powder or solution for preparing soil beds prior to installation of sod, golf course greens and sports turf. The benefits of these biological soil treatments are generally realized only when positioned under the sod or established turf, allowing the use of insecticides, herbicides and fungicides on the laid sod that will not affect the soil treatment.
However, use of biological soil treatments is limited in that once the sod/grass is established, there is no efficient way to reach the roots to treat large areas, or to innoculate areas that did not receive an effective amount of the biological soil treatment formula. In order to ensure a sufficient amount, the tendency is to over-innoculate rather than under innoculate the soil in preparation for laying sod/turf, greatly increasing the expense of the soil treatment.
In particular, U.S. Pat. No. 5,147,441 entitled “Biological Product for Soil Improvement and Method of Application to Soil” issued Sep. 15, 1992, discloses a soil treatment formula which includes adding a nitrogen-fixing Azospirillum species of bacteria to the soil treatment formulation and increasing the cellulosic content to feed the bacteria. In general, these soil treatment formulas are created by experimentation with different bacteria, fungi and nutrients in varying concentrations to determine which combination will work best with the desired plant type and whether used for planting from seed or sod. In particular, during golf course turf construction, on U.S. Golf Association (USGA) sand based greens, there are inadequate levels of soil organisms, this fact contributes to nutrient leaching and poor utilization of plant nutrients.
Currently, the different biological soil treatments are sold commercially as a dry mixture and have a tendency to separate by size over time, essentially requiring greater amounts of the mixture be used to ensure proper soil nutrient management. Examples of these mixtures include, Mycor Turf Saver (Plant Health Care, Pittsburgh, Pa.) and Soil Innoculums (Soil Life Co., Oregon City, Oreg.). These formulations generally contain microbes, fungal spores, and organic nutrients for the plants as well as the developing fungi and bacteria. These dry soil treatments are generally delivered to the soil prior to laying down sod or grass seed using a drop spreader with a tiller which generally results in a 10-15% loss of product during soil inoculation due to wind. Many vendors recommend immediately wetting the soil after inoculation to reduce the amount blown away. Biological soil treatment formulations when prepared in solution generally have a reduced shelf life and require adequate mixing to ensure delivery of the appropriate concentration of the soil treatment.
The narrow region of soil that is directly influenced by the root secretions and associated with soil microorganism is defined as the rhizosphere. In addition, the soil treatments containing microorganisms may be undermined by nematodes and arthropods which feed on the soil bacteria and fungi and limit their effective lifespan. These predators are generally controlled with pesticides which selectively kill the nematodes and arthropods and allow the soil bacteria and fungi to form symbiotic relationships with the plant and facilitate food, water and air usage by the plant's root systems. When the environment is conducive, a higher biological activity significantly reduces nutrient leaching, the majority of plant nutrients are made available to plants via these microorganisms.
Landscapers, greens keepers and sports grounds keepers look for the most cost-effective way to maintain large acres of sports turf, grass and landscapes. They search for the best methods for soil preparation prior to laying new turf and when a soil treatment fails, it is costly to replace these entire areas of dead sod. Therefore, there is a need in the industry to overcome the problem of delivery of biological soil treatments to mature, stable lawns, sports turf and landscaping without disturbing or replacing the sod surface. There is also a need for an improved system of direct delivery of biological soil treatments to the rhizosphere of the root systems with minimal loss of product. A rhizosphere containing an appropriate mixture of biological soil nutrients promotes nourishment and growth of the root systems.
U.S. Pat. No. 4,551,165 entitled “Mycorrhizal Seed Pellets” issued Nov. 5, 1985 (expired) utilized a soil treatment formulation containing the Glomus fungal species which is then embedded in peat moss with the desired seed to form a seed pellet, however it does not include a beneficial bacteria in the formulation. The patent claims that peat moss is superior to clay or sand due to the moisture and nutrient requirements of the seeds.
There are several ways to innoculate the soil with root treatments, including manual soil penetration methods to deliver the biological soil treatments, automated soil penetration equipment or subterranean piping such as an irrigation system. U.S. Pat. No. 5,447,866 entitled “Reactor for Microorganisms and Feed Device Therefore” filed Sep. 5, 1995, discloses a device to take dry soil treatment components, mix with nutrients in a growth media connected to an irrigation system for direct treatment of the soil. However, these types of irrigation systems are more conducive to agricultural crops and are not cost effective for sports arenas and golf courses.
Therefore, there exists a need in the grounds maintenance industry for a biological soil nutrient system which allows application prior to and after sod, turf and greens installation. There also exists a need to rapidly deliver such nutrient systems over large acres of golf greens and sports turf without a rapid turnaround time for their intended use.